Screw-type conduit fitting for a shielded cable

Abstract

The new-type conduit fitting has at least a first, a second and a third part, through each part passes a hole which allows the parts to be pushed axially over the cable. The first part can be connected to a housing in an electrically conductive manner and can be axially tensioned with the third part. The second part is electrically conductive, and it reduces the cross section of its hole with increasing axial tensioning between the first and third parts. The hole of the first part expands conically against the second part, wherein the second part is a annular sleeve with a sheathing surface conically tapering against the first part and with a cylindrical inner surface, and the development of the annular sleeve has a shape meandering in a zigzag pattern. A fourth part formed as a rubber sleeve is positioned around the cable, and a fifth part formed as a union nut compresses the rubber sleeve between the union nut and the third part.

What is claimed is: 
     
       1. A conduit fitting for a shielded cable, the fitting comprising: a first part having a hole through which the cable can pass, said hole having a conically expanding shape, said first part having means for electrically connecting to a housing; a second part having a hole with a cylindrical inner surface through which said cable can pass and formed as an annular sleeve of the cable, said second part being formed of electrically conductive material;   a third part having a hole through which said cable can pass, said third part being connectable to said first part and having a first fastening means for being axially tensioned with said first part, said second part being positionable to fit between said first and third part, said second part having a sheathing surface conically tapering and positionable against said conically expanding shape of said hole of said first part, said second part also being formed in a zig-zag shape for reducing a cross section of said hole of said second part when said first and third part are increasingly axially tensioned.   
     
     
       2. A fitting in accordance with claim 1, further comprising: a fourth part having a hole through which said cable can pass, said fourth part being formed of rubber-elastic material;   a fifth part having a hole through which said cable can pass, said fifth part being connectable to said third part and having a second fastening means for being axially tensioned with said third part on a side of said third part diametrically opposite from said first part, said fourth part being positionable between said third and fifth part, said fourth part being compressible when said third and fifth part are axially tensioned.   
     
     
       3. A fitting in accordance with claim 2, wherein: said first and second fastening means include threaded connections.   
     
     
       4. A fitting in accordance with claim 2, wherein: said fourth part seals an interface between said third part and the cable.   
     
     
       5. A fitting in accordance with claim 1, wherein: said zig-zag shape of said second part is formed by a plurality of incisions alternately extending inwards from opposite axial ends of said second part.   
     
     
       6. A fitting in accordance with claim 1, wherein: said first part is directly electrically, and physically connected to the housing.   
     
     
       7. A fitting in accordance with claim 2, wherein: said second part has reduction limiting means for limiting a reducing of said cross section of said hole of said second part.   
     
     
       8. A fitting in accordance with claim 7, wherein: said reduction limiting means includes flanks in said zig-zag shape which contact each other when a proper amount of reduction has occurred.